<template>
  <div class="app-container">
  <!--查询表单-->
  <el-form :inline="true" class="demo-form-inline">

    <!-- 所属分类：级联下拉列表 -->
    <!-- 一级分类 -->
    <el-form-item label="课程类别">
      <el-select
        v-model="searchObj.subjectParentId"
        placeholder="请选择"
        @change="subjectLevelOneChanged">
        <el-option
          v-for="subject in subjectNestedList"
          :key="subject.id"
          :label="subject.title"
          :value="subject.id"/>
      </el-select>

      <!-- 二级分类 -->
      <el-select v-model="searchObj.subjectId" placeholder="请选择">
        <el-option
          v-for="subject in subSubjectList"
          :key="subject.id"
          :label="subject.title"
          :value="subject.id"/>
      </el-select>
    </el-form-item>
    <!-- 标题 -->
    <el-form-item>
      <el-input v-model="searchObj.title" placeholder="课程标题"/>
    </el-form-item>
    <!-- 讲师 -->
    <el-form-item>
      <el-select
        v-model="searchObj.teacherId"
        placeholder="请选择讲师">
        <el-option
          v-for="teacher in teacherList"
          :key="teacher.id"
          :label="teacher.name"
          :value="teacher.id"/>
      </el-select>
    </el-form-item>
    <el-select
      v-model="searchObj.status"
      placeholder="请选择课程状态">
      <el-option
        v-for="statusa in statuslist"
        :key="statusa"
        :value="statusa"/>
    </el-select>
    <el-button type="primary" icon="el-icon-search" @click="fetchData()">查询</el-button>
    <el-button type="default" @click="resetData()">清空</el-button>
  </el-form>
    <!-- 表格 -->
    <el-table
      v-loading="listLoading"
      :data="list"
      element-loading-text="数据加载中"
      border
      fit
      highlight-current-row
      row-class-name="myClassList">

      <el-table-column
        label="序号"
        width="70"
        align="center">
        <template slot-scope="scope">
          {{ (page - 1) * limit + scope.$index + 1 }}
        </template>
      </el-table-column>

      <el-table-column label="课程信息" width="470" align="center">
        <template slot-scope="scope">
          <div class="info">
            <div class="pic">
              <img :src="scope.row.cover" alt="scope.row.title" width="150px">
            </div>
            <div class="title">
              <a href="">{{ scope.row.title }}</a>
              <p>{{ scope.row.lessonNum }}课时</p>
            </div>
          </div>

        </template>
      </el-table-column>
      <el-table-column label="课程状态" align="center">
        <template slot-scope="scope">
          {{ scope.row.status=='Normal'?"已发布":"未发布" }}
        </template>
      </el-table-column>
      <el-table-column label="创建时间" align="center">
        <template slot-scope="scope">
          {{ scope.row.gmtCreate.substr(0, 10) }}
        </template>
      </el-table-column>
      <el-table-column label="发布时间" align="center">
        <template slot-scope="scope">
          {{ scope.row.gmtModified.substr(0, 10) }}
        </template>
      </el-table-column>
      <el-table-column label="价格" width="100" align="center" >
        <template slot-scope="scope">
          {{ Number(scope.row.price) === 0 ? '免费' :
          '¥' + scope.row.price.toFixed(2) }}
        </template>
      </el-table-column>
      <el-table-column prop="buyCount" label="付费学员" width="100" align="center" >
        <template slot-scope="scope">
          {{ scope.row.buyCount }}人
        </template>
      </el-table-column>

      <el-table-column label="操作" width="150" align="center">
        <template slot-scope="scope">
          <router-link :to="'/course/info/'+scope.row.id">
            <el-button type="text" size="mini" icon="el-icon-edit">编辑课程信息</el-button>
          </router-link>
          <router-link :to="'/course/chapter/'+scope.row.id">
            <el-button type="text" size="mini" icon="el-icon-edit">编辑课程大纲</el-button>
          </router-link>
          <el-button type="text" size="mini" icon="el-icon-delete" @click="removeDataById(scope.row.id)">删除</el-button>
        </template>
      </el-table-column>
    </el-table>

    <!-- 分页 -->
    <el-pagination
      :current-page="page"
      :page-size="limit"
      :total="total"
      style="padding: 30px 0; text-align: center;"
      layout="total, prev, pager, next, jumper"
      @current-change="fetchData"
    />
  </div>
</template>
<script>
  import course from '@/api/edu/course'
  import teacher from '@/api/edu/teacher'
  import subject from '@/api/edu/subject'

  export default {

    data() {
      return {
        listLoading: true, // 是否显示loading信息
        list: null, // 数据列表
        total: 0, // 总记录数
        page: 1, // 页码
        limit: 10, // 每页记录数
        statuslist:['Draft','Normal'],
        searchObj: {
          subjectParentId: '',
          subjectId: '',
          title: '',
          teacherId: '',
          status:'',
        }, // 查询条件
        teacherList: [], // 讲师列表
        subjectNestedList: [], // 一级分类列表
        subSubjectList: [] // 二级分类列表,
      }
    },

    created() { // 当页面加载时获取数据
      this.fetchData()
      // 初始化分类列表
      this.initSubjectList()
      // 获取讲师列表
      this.initTeacherList()
    },

    methods: {
      fetchData(page = 1) { // 调用api层获取数据库中的数据
        this.page = page
        this.listLoading = true
        course.getPageList(this.page, this.limit, this.searchObj).then(response => {
          // debugger 设置断点调试
          if (response.success === true) {
            this.list = response.data.rows
            this.total = response.data.total
          }
          this.listLoading = false
        })
      },

      initTeacherList() {
        teacher.getList().then(response => {
          this.teacherList = response.data.item
        })
      },

      initSubjectList() {
        subject.getNestedTreeList().then(response => {
          this.subjectNestedList = response.data.items
        })
      },

      subjectLevelOneChanged(value) {
        for (let i = 0; i < this.subjectNestedList.length; i++) {
          if (this.subjectNestedList[i].id === value) {
            this.subSubjectList = this.subjectNestedList[i].children
            this.searchObj.subjectId = ''
          }
        }
      },

      resetData() {
        this.searchObj = {}
        this.subSubjectList = [] // 二级分类列表
        this.fetchData()
      },

      removeDataById(id) {
        // debugger
        this.$confirm('此操作将永久删除该课程，以及该课程下的章节和视频，是否继续?', '提示', {
          confirmButtonText: '确定',
          cancelButtonText: '取消',
          type: 'warning'
        }).then(() => {
          return course.removeById(id)
        }).then(() => {
          this.fetchData()
          this.$message({
            type: 'success',
            message: '删除成功!'
          })
        }).catch((response) => { // 失败
          if (response === 'cancel') {
            this.$message({
              type: 'info',
              message: '已取消删除'
            })
          }
        })
      },
    }
  }
</script>

<style scoped>
  .myClassList .info {
    width: 450px;
    overflow: hidden;
  }
  .myClassList .info .pic {
    width: 150px;
    height: 90px;
    overflow: hidden;
    float: left;
  }
  .myClassList .info .pic a {
    display: block;
    width: 100%;
    height: 100%;
    margin: 0;
    padding: 0;
  }
  .myClassList .info .pic img {
    display: block;
    width: 100%;
  }
  .myClassList td .info .title {
    width: 280px;
    float: right;
    height: 90px;
  }
  .myClassList td .info .title a {
    display: block;
    height: 48px;
    line-height: 24px;
    overflow: hidden;
    color: #00baf2;
    margin-bottom: 12px;
  }
  .myClassList td .info .title p {
    line-height: 20px;
    margin-top: 5px;
    color: #818181;
  }
</style>
